Fig. 3

Metabolic imbalances and key expression differences at growth-limiting pH values. A proton-pumping F₀F₁-ATPase maintains ∆pH (i). Glycolysis intermediates accumulate indicating inhibition of flux (ii). Valine transport (iii) and glutamine synthetase activity (iv) and chaperones that protect cytoplasmic macromolecules (v) consume ATP. ATP is preserved directly via downregulation of flagella biosynthesis and motility and other ATP-utilizing functions (vi), and indirectly by downregulation of proton-channeling motility genes MotAB (vii). ATP-independent PP_iase proton pump (viii). Dark green and red proteins are ones whose genes were up and downregulated, respectively. Dark red metabolites were ones that accumulated